WASHINGTON - We should talk honestly about unresolved racial issues, such as those exposed by the Trayvon Martin case, but President Obama is not the best person to lead the discussion. Through no fault of his own, he might be the worst.

The need for what diplomats call a "full and frank exchange of views" is obvious. Many Americans don't even agree that there are unresolved racial issues, much less that such issues played a role in George Zimmerman's acquittal. It's as if some of us live on different planets.

I find it impossible to imagine the outcome would have been the same if the protagonists' roles were reversed -- if Zimmerman had been the victim and Martin the defendant. I know, however, that there are many people who believe the hoodie-wearing African-American teenager would have been accorded the same benefit of the doubt his killer was given. I also know that one's beliefs about race and racism tend to be highly correlated with one's experience of race and racism.

What we're doing now, in an awkward and uncomfortable way, is talking about those beliefs and experiences -- shouting about them, actually. For better or for worse, this seems to be the way we conduct the "national conversation about race" that thoughtful people are always recommending.

Here's how it works: Something happens that makes the subject of race all but unavoidable. We stake out our positions. We get all worked up. We start to get frustrated. Gradually we lose focus and the dialogue, such as it was, peters out. No one feels we've made any headway. Often we have, though the progress may not be evident for some time.

Maybe it would be better if we all gathered at public libraries on some appointed day and worked our way through an agenda: "Legacy of Slavery," check. "Jim Crow Segregation," check. "Affirmative Action," check.

Sounds awfully boring to me, to tell the truth. And in any event, it's never going to happen. For people who want to talk about race, there are plenty of outlets, venues and forums -- more than ever, in fact, with the rise of social media. But those who prefer to avoid the subject are not likely to be enticed by earnestness.

Nor do they respond well, evidence suggests, to the observations and oratory of the first African-American president when he talks about race. It's not the way things ought to be or the way I'd like them to be, but it's the way things are.

The record indicates that honest talk from Obama about race is seen by many people as threatening. A classic example came just months into his first term, when a white police officer in Cambridge, Mass., had an unpleasant encounter with Harvard University professor Henry Louis Gates Jr., who is black, and ended up arresting the famous scholar on his own front porch.

Speaking off the cuff at a news conference, Obama said the officer had "acted stupidly." The remark seemed innocuous to me, a mere statement of fact. It might have been the departure point for a nuanced examination of what happens when race intersects class. Instead, Obama unintentionally provoked such outrage and counter-outrage that he invited the two men to the White House for a photo-op "beer summit" as a way of chilling everyone out.

Similarly, Obama's factual statement that "if I had a son, he'd look like Trayvon" drew shrieks of accusation that the president was unfairly taking sides in a criminal case. His statement following Saturday's verdict was anodyne and forgettable. Perhaps that's for the best.

The designation "first black (fill in the blank)" always brings with it unfair burdens, and one of Obama's -- he bears many -- is that almost anything he says about race will be seen by some as favoring the interests of black Americans over white Americans.

On Friday, Obama tried to frame African-Americans' passion about the Zimmerman verdict in the historical context of discrimination and racial profiling. At the same time, he offered the hopeful view that "as difficult and challenging as this whole episode has been ... things are getting better." Perhaps this intervention will be more productive.

But Obama does more to change racial attitudes and challenge prejudices simply by performing his functions as head of state and commander in chief. A dozen speeches about the long struggle for racial equality and justice would not have the impact of one picture of the first family -- the proud, African-American first family -- walking across the White House lawn. No caption necessary.